This review compared conventional therapies versus adjuvant phytotherapy in treating patients with cervical cancer. The authors concluded that adjuvant phytotherapy may increase survival and tumour regression rates and decrease vesical complications, but that the results require verification. This cautious conclusion appears to reliably reflect limited evidence from the generally poor quality available trials.

Authors’ objectives
To compare the efficacy and safety of conventional therapies with conventional therapies plus adjuvant phytotherapy in the treatment of cervical cancer.

Searching
Forty-three electronic databases were searched, including MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), AMED, several Chinese data sources (listed in the paper) and other databases (e.g. WorldCat, MetaPress, SpringerLink, Oxford Journals Online, Blackwell Synergy, ScienceDirect, and ProQuest). Search terms were reported. Sources of unpublished material, such as the China Proceedings of Conference Databases and China Doctorate/Master Dissertations Full Text Databases, were also searched. Reference lists of retrieved papers were scanned. Handsearching of the latest articles in selected University libraries (details given) was carried out to June 2008. There were no language restrictions.

Study selection
Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that compared the effects and safety of conventional therapies plus phytotherapy with conventional therapies alone; or those comparing phytotherapy, or phytotherapy plus Western medication with Western medication alone, in women with histopathologically confirmed cervical cancer, were eligible for inclusion in the review. Patients receiving non-oral phytotherapy treatments were excluded.

Eligible outcomes were survival rate, tumour regression rate, and vesical or rectal complications.
Over half of included patients were classified with advanced stage cervical cancer (stage IIB and above); the majority of cases were squamous cell carcinoma. Intervention durations ranged from five days to 10 years. Just over half of the included trials measured survival rate and tumour regression rate; the remainder measured vesical or rectal complications. The most frequently used phytotherapeutic herbs amongst the included trials were reported; just under half of trials used Radix astragali.

Assessment of study quality
Trial quality was assessed using the Jadad criteria, covering randomisation, double-blinding, and drop-out rate. Trials were scored from 1 to 5, where trials scoring 1 and 2 were considered to be low quality, and trials scoring 3 to 5 were considered high quality.

Results of the review
Eighteen RCTs (n=1,657 patients) were included in the review. Two trials were considered to be high quality (with Jadad scores of 3); the remainder were low quality (Jadad scores of 0 and 1). Two trials that compared phytotherapy plus Western medications with Western medications alone appeared to be part of the same study, raising the possibility of duplicate analysis of patients.

CRD commentary
The review addressed a clear question, and this was supported by detailed and potentially reproducible inclusion criteria. The search strategy included an extensive list of data sources, and efforts were made to minimise language and publication biases. The review process was carried out with some attempts to minimise error and bias in the selection of studies and data extraction. The process was unreported for validity assessment.

An appropriate validity assessment tool was applied to the trials, revealing that the evidence was generally of poor quality. Trial details were provided, and this revealed the possibility of double-counting of patients. The chosen method of synthesis appeared to be appropriate in most cases; sub-group analysis was carried out to explore the effect of heterogeneity.

Implications of the review for practice and research
Practice: The authors stated that adjuvant phytotherapy should be of value to improve the survival rate of patients, including those at the advance stages of cervical cancer.

Research: The authors stated that further large-scale, long-term RCTs are needed to verify the results of this review, and examine the effects of phytotherapy in treating cervical cancer, specifically in patients with vesical complications resulting from conventional therapies. Research should also focus on the commonly-used herbs identified in this review.